Yeah, meanwhile I've read several discussions about this easy. What I
learned so far:

- There are plenty of people with security concerns about this.
- There are plenty of other people ignoring these concerns.
- There is not a single good reason to deliver archive files with
world writable permissions. Until now I just found that it is made
intentionally, but no good reason.

The standard recommendation is to never compile
the kernel as root.

So how would you do

make install
make modules_install

then? This recommendation works only for generating kernel packages,
but not for local installation.

If this was a standard recommendation, why has the Makefile the
install and modules_install clause at all?

And if this is a standard recommendation, it is not sufficiently
published. If it were, the Makefile itself would tell you